Metal, Air Gap Kits and Caps

An air gap kit and cap is a plumbing device required by some communities that prevents wastewater backflow from entering the dishwasher and the potable water supply. It provides airflow, preventing a vacuum from causing a reverse flow of water. The drain from the dishwasher is connected to the smaller of the two tubes allowing for water from the dishwasher to be pumped up through it and shoot against the air gap cap. The wastewater falls through the larger tube of the air gap kit and drains toward the garbage disposer.